Dr. Kristina Keating’s research focuses on using near surface geophysics to investigate the top 100 m’s of Earth’s surface. In particular, she is interested in using near-surface geophysics for hydrogeologic, biogeochemical, and cryosphere investigations. Dr. Keating uses standard geophysical methods including seismic refraction and electrical resistivity, but much of her research is focused on a novel geophysical method, nuclear magnetic resonance (NMR). Past and on-going studies in her research group includes field investigations to understand the depth and distribution of permafrost in Svalbard, laboratory studies to improve geophysical estimations of hydraulic conductivity, and computer modeling to improve the interpretation and analysis of geophysical data.
Exploring Controls on Ecosystem Function and the Role of Conservation Practices in Agricultural Streams
Webinar Format: Zoom
Access Information Here
Speaker: Dr. Brittany Hanrahan, United States Department of Agriculture
Over the past 150 years, much of the Midwestern US has been converted from prairies and wetlands to intensive row crop productions of corn and soybeans. The effects of agricultural land use, including riparian vegetation removal, substrate homogenization, and altered hydrologic regimes, manifest as a complex array of physical and chemical changes to stream ecosystems that influence biogeochemical cycling. As a result, agricultural watersheds, also known as “agroecosystems”, export excess nitrogen (N) and phosphorus (P), causing numerous water quality problems including drinking water contamination, loss of biodiversity, and eutrophication of downstream freshwaters and coastal zones. In this talk, I will examine the linkages between terrestrial land cover and stream ecosystem function and highlight the role of abiotic controls on ecosystem processes, like nutrient uptake and ecosystem metabolism. I will also demonstrate the influence of conservation practices, including floodplain restoration and watershed-scale land cover change, on nutrient loss from a small, agricultural watershed. Finally, I will discuss the challenges and benefits of quantifying the effects of conservation efforts across spatial and temporal scales.